oniro-linux.conf: Include openharmony.inc for openharmony-specific conf

The most important elements of this include file is the OpenHarmony
version definition along with the associated preferred version.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-oniro-core/conf/distro/oniro-linux.conf

@@ -115,3 +115,4 @@ SPLASH = "psplash-oniro"
 
 DISTRO_FEATURES_FILTER_NATIVE:append = " openharmony"
 DISTRO_FEATURES_FILTER_NATIVESDK:append = " openharmony"
+require conf/distro/include/openharmony.inc